The present invention generally pertains to light reflective films. More specifically, the present invention pertains to multi-layered structures having a light-reflective material in which the multi-layered structures are encapsulated with a transparent coating. The present invention can provide light reflective devices which effectively reflect light, even when wet, and are highly flexible. In an embodiment, the present invention pertains to a flexible film or fabric having a multi-layered, light-reflective structure on a web in which the structure and the web are encapsulated with a flexible coating.
Devices which reflect light are known, including reflective tapes. However, needs exist for improved light reflecting devices, and existing reflective tapes can be improved.
FIG. 1 shows a cross-section of an existing reflective tape 10, which is an open-type reflective tape. The open-type reflective tape 10 has a base sheet 12 which reflects light. The open-type reflective tape 10 also has clear glass spherical beads 14 on the reflective base sheet 12. The glass spherical beads 14 are bare and exposed to the surrounding environment. Also, portions of the reflective base sheet 12 between the glass spherical beads 14 are exposed to the surrounding environment.
Although the open-type reflective tape 10 reflects light, the open-type reflective tape 10 can have disadvantages. The glass spherical beads 14 are bare and exposed to the environment. The glass spherical beads 14 are susceptive to the environmental elements because the beads 14 are exposed. The exposed structure of the glass spherical beads 14 can hinder light reflection by the open-type reflective tape 10. For example, when the open-type reflective tape 10 becomes wet, such as when used in water or rain, the ability of the open-type reflective tape 10 to reflect light can be significantly reduced or even effectively eliminated. Similarly, the exposed portions of the reflective base sheet 12 are susceptive to the environmental elements which can hinder light reflection.
FIG. 2 shows a cross-section of another existing reflective tape 16, which is a closed-type reflective tape. The closed-type reflective tape 16 has a base sheet 18 which reflects light and clear glass spherical beads 20. The glass spherical beads 20 are completely, tightly coated with plastic resin 22. Also, the plastic resin 22 contacts and covers the light reflective base sheet 18. The plastic resin 22 of the closed-type reflective tape 16 may protect the glass spherical beads 20 from the elements of the surrounding environment.
However, the closed-type reflective tape 16 can have disadvantages. Particularly, the closed-type reflective tape 16 can have reduced ability to reflect light. The light reflective base sheet 18 is covered by and in contact with the plastic resin 22. There is no air space immediately above the light reflective base sheet 18. The plastic resin 22 covering and in contact with the base sheet 18 tends to reduce the light-reflective ability of the closed-type reflective tape 16. Also, the plastic resin 22 has a relatively high thickness to cover the glass spherical beads 20. The thickness of the plastic resin 22 tends to darken the plastic resin 22 and reduce its clearness or ability to permit light transmission. Accordingly, the light-reflectiveness of the closed-type reflective tape 16 is reduced. When water contacts the closed-type reflective tape 16, the light reflection is reduced even further. Furthermore, the thickness of the plastic resin 22 stiffens the closed-type reflective tape 16 which reduces the tape's flexibility.
FIG. 3 shows a cross-section of another existing reflective tape 24, which is a capsule-type reflective tape. The capsule-type reflective tape 24 has a base sheet 26 and clear glass spherical beads 28. The base sheet 26 forms posts 30 between various glass spherical beads 28. Only one post 30 is shown in FIG. 3; however, numerous posts 30 extend upward above the glass spherical beads 28. A plastic film 32 is bonded to the tops of the posts 30. The posts 30 provide a gap 34 between the plastic film 32 and the glass spherical beads 28.
The capsule-type reflective tape 24 may provide increased light reflectiveness compared to the closed-type reflective tape 16 (FIG. 2). However, the capsule-type reflective tape 24 can have disadvantages. The posts 30 of the capsule-type reflective tape 24 increase the rigidity of the tape 24. Thus, the capsule-type reflective tape 24 has reduced flexibility.
The open-type reflective tape 10, closed-type reflective tape 16, and capsule-type reflective tape 24 can exhibit further disadvantages. For example, existing reflective tapes tend to have low surface protection and low abrasive resistance. Accordingly, objects can contact and damage the tapes which reduces the effectiveness of light reflection. Use of existing tapes in cold temperatures or cold weather tends to reduce the flexibility of the tapes. Also, existing tapes have significantly lower light reflection in wet environments.
Accordingly, for the reasons mentioned above and for other reasons, light reflective tapes can be improved. For example, one improvement would be to provide a light reflective film that reflects light very well and is flexible.
Existing light reflective tapes can also be found in U.S. Pat. Nos. 5,637,173; 5,728,448; 5,805,339; 5,956,818; 6,114,011; and 6,180,545 B1; and Japanese Patent Application Nos. S48-103559 (Japanese Publication No. S50-53661); H07-144163 (Japanese Publication No. H08-309929); and S58-51359 (Japanese Publication No. S59-157819).